Как правильно использовать HashMap?

for (Object key : instance.keySet())
    if (что то)
        instance.remove(key);

for(Iterator<Map.Entry<String, CompanyObject>> it = instance.entrySet().iterator(); it.hasNext(); ) {
      Map.Entry<String, CompanyObject> entry = it.next();
      if(что то) {
        it.remove();
      }
    }

for (Object obj : new ArrayList<Object>(instance.keySet()))
    if (что то)
        instance.remove(key);

public class CouponSystemUsersDataSetter {

   private static CouponSystemBeanFactory couponBeanFactory = CouponSystemBeanFactory.getCouponSystemBeanFactoryInstance();

   private static CompanyServiceTesting companyServiceTesting = CompanyServiceTesting.companyServiceTestingInstance();
   private static AdminServiceTesting adminServiceTesting = AdminServiceTesting.getAdminServiceTestingInstance();

    public static Map<String,Object> getInstances() {
        return instances;
    }

    private static Map<String,Object> instances = new HashMap<>();


    private RegistrationData callForRegistration(){
        return couponBeanFactory.getBeanInstance("registration" , RegistrationData.class);
    }

    private static Company callForCompany(){
        return couponBeanFactory.getBeanInstance("company" , Company.class);
    }

    private static Coupon callForCoupon(){
        return couponBeanFactory.getBeanInstance("coupon" , Coupon.class);
    }

    private Customer callForCustomer(){
        return couponBeanFactory.getBeanInstance("customer",Customer.class);
    }

    private Employee callForEmployee(){
        return couponBeanFactory.getBeanInstance("employee",Employee.class);
    }

    private User callForUser(){
        return couponBeanFactory.getBeanInstance("user",User.class);
    }

    @Before
   public  void createCoupons(){
        System.out.println("Setting coupons data! ");
        Map<String,Object> instances = getInstances();
        instances.put("coupon1",companyServiceTesting.createCompanyCoupon((Company)instances.get("company1"),callForCoupon(),"Travelling low prices","FamilyTravelling",
                23,765475475,"C://ProgramFiles",35.8, CouponType.TRAVELING, CouponSystemDate.dateFormat(2017,12,12)
                ,CouponSystemDate.dateFormat(2019,12,12)));

       instances.put("coupon2",companyServiceTesting.createCompanyCoupon((Company)instances.get("company2"),callForCoupon(),"Camping low prices","FamilyCamping",
                13,9999887,"C://ProgramFiles",55.8, CouponType.CAMPING, CouponSystemDate.dateFormat(2016,10,10)
                ,CouponSystemDate.dateFormat(2018,9,1)));

       instances.put("coupon3",companyServiceTesting.createCompanyCoupon((Company)instances.get("company1"),callForCoupon(),"Electricity low prices","Electricity",
               12,5424352,"C://ProgramFiles",25.8, CouponType.ELECTRICITY, CouponSystemDate.dateFormat(2017,7,3)
               ,CouponSystemDate.dateFormat(2018,4,5)));

       instances.put("coupon4",companyServiceTesting.createCompanyCoupon((Company)instances.get("company2"),callForCoupon(),"Food low prices","FamilyDinner",
               53,989873,"C://ProgramFiles",15.8, CouponType.FOOD, CouponSystemDate.dateFormat(2017,4,11)
               ,CouponSystemDate.dateFormat(2018,4,11)));

       instances.put("coupon5",companyServiceTesting.createCompanyCoupon((Company)instances.get("company1"),callForCoupon(),"Health insurance low prices","FamilyInsurance",
               83,33344455,"C://ProgramFiles",88.8, CouponType.HEALTH, CouponSystemDate.dateFormat(2017,8,9)
               ,CouponSystemDate.dateFormat(2018,8,9)));

       instances.put("coupon6",companyServiceTesting.createCompanyCoupon((Company)instances.get("company2"),callForCoupon(),"Sport village low prices","SportVacation",
               73,6665432,"C://ProgramFiles",95.8, CouponType.SPORTS, CouponSystemDate.dateFormat(2017,7,11)
               ,CouponSystemDate.dateFormat(2019,7,11)));
   }

    @BeforeClass
   public static void createCompanies(){
        System.out.println("Setting companies data! ");
        Map<String,Object> instances = getInstances();
       instances.put("company1",adminServiceTesting.createCompany("ORG","Free@88",34553453,"ORG@.com",callForCompany()));
       instances.put("company2",adminServiceTesting.createCompany("PPP","Trading@000",4536579,"PPP@.com",callForCompany()));
   }

    @Test
   public void createCustomers(){
        System.out.println("Setting customer data! ");
        Map<String,Object> instances = getInstances();
       instances.put("customer1",companyServiceTesting.createCustomer(787654,"Natali@gmail.com","Nata000@99","Nata","Vladimi",callForCustomer()));
       instances.put("customer2",companyServiceTesting.createCustomer(980982,"Maks@gmail.com","MMM@mmm999","Maks","Burkov",callForCustomer()));
       instances.put("customer3",companyServiceTesting.createCustomer(888776655,"Sasha@gamil.com","SSS0001988@","Sasha","Sashkoviz",callForCustomer()));
       instances.put("customer4",companyServiceTesting.createCustomer(4443332,"Lumila@gmail.com","lumi00088@","Lumila","Lumovich",callForCustomer()));
       instances.put("customer5",companyServiceTesting.createCustomer(222888444,"Yani@gmail.com","yani@_777","Yani","Yovi",callForCustomer()));
       instances.put("customer6",companyServiceTesting.createCustomer(4325432,"Yoni@gmail.com","Yoni@09087","Yoni","Yonivich",callForCustomer()));
   }

    @Before
   public void createEmployees(){
        System.out.println("Setting employee data! ");
        Map<String,Object> instances = getInstances();
       instances.put("employee1",companyServiceTesting.createCompanyEmployee(callForEmployee(),(Company)instances.get("company1"),222222,"Rahel@gmail.com","Israel","Rahel","Rehelovich","059876534"));
       instances.put("employee2",companyServiceTesting.createCompanyEmployee(callForEmployee(),(Company)instances.get("company2"),111111,"Yosi@gmail.com","Israel","Yosi","Izhak","055312567"));
       instances.put("employee3",companyServiceTesting.createCompanyEmployee(callForEmployee(),(Company)instances.get("company1"),45353,"Pavel@gmail.com","Israel","Pavel","Pavlov","050689321"));
       instances.put("employee4",companyServiceTesting.createCompanyEmployee(callForEmployee(),(Company)instances.get("company2"),3498766,"Luba@gmail.com","Israel","Luba","Lubovkina","0547890122"));
       instances.put("employee5",companyServiceTesting.createCompanyEmployee(callForEmployee(),(Company)instances.get("company1"),8888453,"Miha@gmail.com","Israel","Miha","Mihuelkin","050934122"));
       instances.put("employee6",companyServiceTesting.createCompanyEmployee(callForEmployee(),(Company)instances.get("company2"),9879874,"Avi@gmail.com","Israel","Avi","AviAla","0547334567"));
   }

    @After
   public void createUsers(){
        System.out.println("Setting users data! ");
        Map<String,Object> instances = getInstances();
       Customer c1 = (Customer) instances.get("customer1"); Customer c2 = (Customer) instances.get("customer2");  Customer c3 = (Customer) instances.get("customer3");
       Customer c4 = (Customer) instances.get("customer4"); Customer c5 = (Customer) instances.get("customer5");  Customer c6 = (Customer) instances.get("customer6");

       instances.put("user1",RegisterServiceTesting.createUser("Customer1",c1.getPassword(),c1.getEmail(),"customer",callForUser()));
       instances.put("user2",RegisterServiceTesting.createUser("Customer2",c2.getPassword(),c2.getEmail(),"customer",callForUser()));
       instances.put("user3",RegisterServiceTesting.createUser("Customer3",c3.getPassword(),c3.getEmail(),"customer",callForUser()));
       instances.put("user4",RegisterServiceTesting.createUser("customer4",c4.getPassword(),c4.getEmail(),"customer",callForUser()));
       instances.put("user5",RegisterServiceTesting.createUser("customer5",c5.getPassword(),c5.getEmail(),"customer",callForUser()));
       instances.put("user6",RegisterServiceTesting.createUser("customer6",c6.getPassword(),c6.getEmail(),"customer",callForUser()));
   }

    @AfterClass
   public static void setLoginData(){
        System.out.println("Setting login data! ");
        Map<String,Object> instances = getInstances();
       instances.put("login1",instances.get("user1"));
       instances.put("login2",instances.get("user2"));
       instances.put("login3",instances.get("user3"));
   }

   @AfterClass
   public static void checkTheSetedObjects(){
       System.out.println("Checking the setted data! ");
       Map<String,Object> instances = getInstances();
       Iterator<Map.Entry<String,Object>> iterator =  instances.entrySet().iterator();
       while (iterator.hasNext()){
          Object value =  iterator.next().getValue();
          System.out.println("Iterated value: "+value);
       }
   }

private static Map<String,Object> instances = null;
public static Map<String,Object> getInstances() {
        if(instances==null){
            instances = new HashMap<>();
        }else
        return instances;
    }

@Before
   public  void createCoupons(){
  instances.put("coupon1",companyServiceTesting.createCompanyCoupon((Company)instances.get("company1"),callForCoupon(),"Travelling low prices","FamilyTravelling",
                23,765475475,"C://ProgramFiles",35.8, CouponType.TRAVELING, CouponSystemDate.dateFormat(2017,12,12)
                ,CouponSystemDate.dateFormat(2019,12,12)));
...

@Before
   public  void createCoupons(){
  Object obj = companyServiceTesting.createCompanyCoupon((Company)instances.get("company1"),callForCoupon(),"Travelling low prices","FamilyTravelling",
                23,765475475,"C://ProgramFiles",35.8, CouponType.TRAVELING, CouponSystemDate.dateFormat(2017,12,12)
                ,CouponSystemDate.dateFormat(2019,12,12))
  instances.put("coupon1",obj);
...

@AfterClass
   public static void checkTheSetedObjects(){
       System.out.println("Checking the setted data! ");
       Map<String,Object> instances = getInstances();
       Iterator<Map.Entry<String,Object>> iterator =  instances.entrySet().iterator();
       while (iterator.hasNext()){
          Object value =  iterator.next().getValue();
          System.out.println("Iterated value: "+value);
       }
   }

System.out.println("Checking the setted data! ");
Map<String,Object> instances = getInstances();
for(Map.Entry<String,Object> entry :instances.entrySet()) {
    String key = entry.getKey();
    Object value = entry.getValue();
   System.out.println("Iterated key: "+key + "   "+"Iterated value: "+value);

Setting companies data! 
Setting employee data! 
Setting coupons data! 
Setting customer data! 
Setting users data! 
Checking the setted data! 
Iterated value: Coupon [id=6665432, title=SportVacation, startDate=2017-07-11, endDate=2019-07-11, amount=73, message=Sport village low prices, price=95.8, image=C://ProgramFiles, type=SPORTS]
Iterated key:coupon6
Iterated value: Coupon [id=6665432, title=SportVacation, startDate=2017-07-11, endDate=2019-07-11, amount=73, message=Sport village low prices, price=95.8, image=C://ProgramFiles, type=SPORTS]
Iterated key:company1
Iterated value: Coupon [id=6665432, title=SportVacation, startDate=2017-07-11, endDate=2019-07-11, amount=73, message=Sport village low prices, price=95.8, image=C://ProgramFiles, type=SPORTS]
Iterated key:company2
Iterated value: Customer{id=4325432, custFirstName='Yoni', custLastName='Yonivich', password='Yoni@09087', email='Yoni@gmail.com'}
Iterated key:coupon4
Iterated value: Customer{id=4325432, custFirstName='Yoni', custLastName='Yonivich', password='Yoni@09087', email='Yoni@gmail.com'}
Iterated key:coupon5
Iterated value: Customer{id=4325432, custFirstName='Yoni', custLastName='Yonivich', password='Yoni@09087', email='Yoni@gmail.com'}
Iterated key:customer5
Iterated value: Customer{id=4325432, custFirstName='Yoni', custLastName='Yonivich', password='Yoni@09087', email='Yoni@gmail.com'}
Iterated key:customer3
Iterated value: User{nickName='customer6', email='Yoni@gmail.com', password='Yoni@09087', role='customer'}
Iterated key:user1
Iterated value: User{nickName='customer6', email='Yoni@gmail.com', password='Yoni@09087', role='customer'}
Iterated key:user5
Iterated value: User{nickName='customer6', email='Yoni@gmail.com', password='Yoni@09087', role='customer'}
Iterated key:user3
Iterated value: Employee{id=9879874, firstName='Avi', lastName='AviAla', email='Avi@gmail.com', phoneNumber='0547334567', country='Israel'}
Iterated key:employee6
Iterated value: Employee{id=9879874, firstName='Avi', lastName='AviAla', email='Avi@gmail.com', phoneNumber='0547334567', country='Israel'}
Iterated key:employee3
Iterated value: Employee{id=9879874, firstName='Avi', lastName='AviAla', email='Avi@gmail.com', phoneNumber='0547334567', country='Israel'}
Iterated key:employee5
Setting login data! 
Test successfully accomplished ? true